Due to the climate change the drought had been occurring more frequently in recent two decades as compared to the previous years. The change in the pattern and frequency of the rainfall have a direct effect on the farming sector; therefore, the quantitative estimation of water supply is necessary for efficient agricultural water reservoir management. In past researches, there had been several studies conducted in estimation and evaluation of water supply based on the irrigational water requirement. However, some researches had shown significant differences between the theoretical and observed data based on this requirement. Thus, this study aims to propose an approach in estimating reservoir rate based on empirical method that utilized observed reservoir rate data. The result of these two methods in comparison with the previous one is seen to be more fitted for both R2 and RMSE with the observed reservoir rate. Among these procedures, the method that considers the drought year data shows more fitted outcomes. In addition, this new method was verified using 15-year (2002 to 2006) linear regression equation and then compare the preceeding 3-year (1999 to 2001) data to the theoretical method. The result using linear regression equation is also perceived to be more closely fitted to the observed reservoir rate data than the one based on theoretical irrigation water requirement. The new method developed in this research can therefore be used to provide more suitable supply data, and can contribute to effectively managing the reservoir operation in the country.
The Effects of Rural Community Business and It’s Performance and Relationship with Residents’ Life Satisfaction - Mediating the Effects of Performance -
정상숙 Jeong Sang Sook , 엄성준 Eom Seong Jun , 조성결 Jo Seung Geul , 리신호 Rhee Shin Ho
The Effects of Rural Community Business and It’s Performance and Relationship with Residents’ Life Satisfaction - Mediating the Effects of Performance -
정상숙 Jeong Sang Sook , 엄성준 Eom Seong Jun , 조성결 Jo Seung Geul , 리신호 Rhee Shin Ho
The purpose of this study was to examine the relationships between the community business, performance and the life satisfaction of local residents and to investigate the mediating effects that community business performance has on the life satisfaction of local residents. The results of the study investigating the effect of community business, performance and the residents’ life satisfaction mediating effect of performance are summarized as follows: First, there were differences with the economical, environmental, and performance factors pertaining to the participants’ age while there were no differences concerning the social-cultural factors and the life satisfaction of local residents. Second, the higher the impact a community business has, the higher the life satisfaction of the local residents have. In addition, the higher the performance in community business, the more ready local residents are to be inclined to be satisfied. Third, economical and environmental factors have direct effects on the life satisfaction of local residents, but also indirectly effect the performance of local residents. In addition, the level of performance that a community business plays has a mediating role in the life satisfaction of local residents.
Response of Crop Water Stress Index (CWSI) and Canopy Temperature of Apple Tree to Irrigation Treatment Schemes
김민영 Kim Minyoung , 최용훈 Choi Yonghun , 조정건 Cho Junggun , 윤석규 Yun Seokkyu , 박정훈 Park Jeonghun , 김영진 Kim Youngjin , 전종길 Jeon Jonggil , 이상봉 Lee Sangbong
Crop response to weather and internal water pressure changes is more sensitive to crop water stress than soil water content. Recently, its implementation to optimal irrigation scheduling has been receiving much attention. This study was conducted to determine and compare the theoretical crop water stress index (CWSI) using meterological data and canopy temperature collected from three different irrigation treatments, which were Tr-1 plot (rainfed), Tr-2 plot (50% of daily evapotranspiration (ET) irrigated) and Tr-3 plot (75% of daily evapotranspiration (ET) irrigated). The readings of canopy temperature and CWSI were significantly different among irrigation treatment schemes. The average canopy temperatures and CWSIs of Tr-1 and Tr-3 plots were 34.6°C and 32.6°C, 0.79 and 0.64, respectively. Solar radiation had the biggest correlation with CWSI (R=0.68) which was followed by wind speed, relative humidity and air temperature. Overall, the findings of this study indicated that canopy temperatures and CWSIs could be further used for irrigation scheduling for crop growth.
A Economic Feasibility Study on Environmental Ecology Flow Supply Plan using Agricultural Reservoir - Focused on Dongbok River -
박진현 Park Jin-hyeon , 고재한 Ko Jae Han , 성무홍 Sung Mu-hong , 정형모 Jung Hyoung-mo , 박태선 Park Tae-sun , 곽영철 Kwak Yeong Cheol , 최우영 Choi Woo-young , 범진아 Boem Jina , 정민혁 Jeung Minhyuk , 유승환 Yoo Seung-hwan , 윤광식 Yoon Kwang-sik
The environmental ecological flow (EEF) of stream or river will be designated according to the enforcement of the Water Environment Preservation Act. Previous researches by Ministry of Environment have proposed agricultural reservoirs as alternative resources to secure river flow where multi-purpose dam does not exist. However, agricultural reservoirs are constructed for the supply of agricultural water, and in fact, there is not a sufficient amount of water to be supplied to rivers as EEF. Therefore, this study examines the economic feasibility of securing EEF through the remodeling or construction of agricultural reservoirs. We investigated water balance of reservoir through simulation of three types of water supply demands such as agricultural water, agricultural water and river maintenance flow, and agricultural water and environmental ecology flow. The economics analysis was conducted on water supply demands and corresponding remodeling or construction of reservoirs. As a result, it was found that the method of securing through heightening existing reservoir enhancement is economically feasible. However, it was not possible to secure all the amount of the EEF due to the size limitation of existing reservoirs or constrain of the watershed for newly built reservoir. Therefore, in order to secure all of the EEF, the utilization of other alternatives as well as agricultural reservoirs should be considered. This study demonstrated the method of economical feasibility study of securing river maintenace flow and EEF using agricultural reservoirs and other considerations.
An Analysis on the Prospects and Realities of Local Governments’ Project Promotions according to the Changes in Financial Policy of Agricultural Infrastructure Improvement Projects
배승종 Bae Seung-jong , 김대식 Kim Dae-sik , 김수진 Kim Soo-jin , 김성필 Kim Seong-pil
An Analysis on the Prospects and Realities of Local Governments’ Project Promotions according to the Changes in Financial Policy of Agricultural Infrastructure Improvement Projects
배승종 Bae Seung-jong , 김대식 Kim Dae-sik , 김수진 Kim Soo-jin , 김성필 Kim Seong-pil
This study attempted to investigate the changes in the perception of local government officials about agricultural infrastructure improvement projects due to the financial policy changes. A total of 141 local government officials were surveyed on the priority, the current status of the agricultural infrastructure improvement projects. Irrigation facilities renovation project and Small drainage improvement project had generally high priority, while Support project of cultivation basis for upland crops in paddy, Large scale land readjustment project, and Upland infrastructure improvement project had low priorities. After the introduction of the block grant system, agricultural infrastructure improvement projects had often been conducted by collecting opinions from local residents. The officials in charge of local governments recognized that the agricultural infrastructure improvement projects were reduced due to lack of financial resources and project potential sites. In response to the changes in the agricultural infrastructure improvement projects, most of the surveys showed that the influence of cities and provinces was strengthened. In addition, respondents most needed to improve the subsidy rate and there were a large number of cases requiring differential support to meet the characteristics of the local government. Therefore, it will be necessary to present a new perspective on the agricultural infrastructure improvement projects and to suggest differentiated projects for each regions.
A Study on Public Effect of Rural Tourism Development Project on the Rural Community
박미정 Park Meejeong , 전정배 Jeon Jeongbae , 손호기 Son Hogi , 신민지 Shin Minji , 박로운 Park Roun
Rural tourism has been identified as providing opportunities to revitalize the rural economies since early 2000s. During last decade in South Korea, government has enacted many policies aiming to establish tourism support programs as well as instigating activities between rural and nearby urban districts. In particular, the promotion of the rural tourism has been actively sought in various forms of products and services, such as green tourism village, village festival, one-company one-village campaign and etc. However, in order to prepare effective policies, it is very crucial to identify measureable evaluation criteria that can be used to assess socio-economic situations of the rural districts. Such criteria should be objective, timely and provide insights about living conditions of local residents and relevant properties. They can also be used to evaluate if progress is being made after the policies are implemented. While considerable efforts and resources have been invested to aid the tourism programs in South Korea, we still lack such systematic means to quantify and evaluate its impact on rural districts. In this work, we have applied regional deprivation analysis on well-established community experiential and recreational business in rural villages throughout the country based on three criteria (i.e., population, local commerce, and buildings). Surprisingly, the result shows that the implementation of the community experiential and recreational businesses did not bring any noticeable changes to at least one of the evaluation criteria. We concluded that the current government policies on revitalization of rural tourism at the village scale is insufficient for bringing meaningful socio-economic impacts to rural districts, with rare exceptions.
Estimation of the Hapcheon Dam Inflow Using HSPF Model
The objective of this study was to calibrate and validate the HSPF (Hydrological Simulation Program-Fortran) model for estimating the runoff of the Hapcheon dam watershed. Spatial data, such as watershed, stream, land use, and a digital elevation map, were used as input data for the HSPF model. Observed runoff data from 2000 to 2016 in study watershed were used for calibration and validation. Hydrologic parameters for runoff calibration were selected based on the user’s manual and references, and trial and error method was used for parameter calibration. The R2, RMSE (root-mean-square error), RMAE (relative mean absolute error), and NSE (Nash-Sutcliffe efficiency coefficient) were used to evaluate the model’s performance. Calibration and validation results showed that annual mean runoff was within ±4% error. The model performance criteria for calibration and validation showed that R2 was in the rang of 0.78 to 0.83, RMSE was 2.55 to 2.76 mm/day, RMAE was 0.46 to 0.48 mm/day, and NSE was 0.81 to 0.82 for daily runoff. The amount of inflow to Hapcheon Dam was calculated from the calibrated HSPF model and the result was compared with observed inflow, which was -0.9% error. As a result of analyzing the relation between inflow and storage capacity, it was found that as the inflow increases, the storage increases, and when the inflow decreases, the storage also decreases. As a result of correlation between inflow and storage, R2 of the measured inflow and storage was 0.67, and the simulated inflow and storage was 0.61.
Applicability of Optical Particle Counters for Measurement of Airborne Pesticide Spray Drift
With desires for safe food, there is growing concern that pesticide spray drift will expose people, plants, and the environment to pesticide residue and potential negative effects thereof. For highly efficient, safe spray application, technologies for measuring the spray drift should be developed and improved with some urgency. This study investigated the applicability of two optical particle counters (OPCs), which are mostly used to measure airborne particle mass concentration, for measurement of airborne pesticide spray drift. Experiments were conducted in a controlled laboratory and an ash tree orchard to evaluate the handiness and accuracy of two OPCs, OPC 1 and OPC 2. The experimental results indicated that the OPC 1 was better applicable to the measurement of spray drift in the field while the use of the OPC 2 was limited due to its narrow range of measurable droplet sizes. The readings of the OPC 1 produced highly accurate results (R2=0.9637) compared to the actual spray drift. For better application of OPCs, this study suggests the OPCs should be positioned properly to inhale spray droplets of the appropriate size and concentration.
Estimation of High-Resolution Soil Moisture based on Sentinel-1A/B SAR Sensors
김상우 Kim Sangwoo , 이태화 Lee Taehwa , 신용철 Shin Yongchul
In this study, we estimated the spatially-distributed soil moisture at the high resolution (10 m×10 m) using the satellite-based Sentinel-1A/B SAR (Synthetic Aperture Radar) sensor images. The Sentinel-1A/B raw data were pre-processed using the SNAP (Sentinel Application Platform) tool provided from ESA (European Space Agency), and then the pre-processed data were converted to the backscatter coefficients. The regression equations were derived based on the relationships between the TDR (Time Domain Reflectometry)-based soil moisture measurements and the converted backscatter coefficients. The TDR measurements from the 51 RDA (Rural Development Administration) monitoring sites were used to derive the regression equations. Then, the soil moisture values were estimated using the derived regression equations with the input data of Sentinel-1A/B based backscatter coefficients. Overall, the soil moisture estimates showed the linear trends compared to the TDR measurements with the high Pearson’s correlations (more than 0.7). The Sentinel-1A/B based soil moisture values matched well with the TDR measurements with various land surface conditions (bare soil, crop, forest, and urban), especially for bare soil (R: 0.885∼0.910 and RMSE: 3.162∼4.609). However, the Mandae-ri (forest) and Taean-eup (urban) sites showed the negative correlations with the TDR measurements. These uncertainties might be due to limitations of soil surface penetration depths of SAR sensors and complicated land surface conditions (artificial constructions near the TDR site) at urban regions. These results may infer that qualities of Sentinel-1A/B based soil moisture products are dependent on land surface conditions. Although uncertainties exist, the Sentinel-1A/B based high-resolution soil moisture products could be useful in various areas (hydrology, agriculture, drought, flood, wild fire, etc.).
Assessment of Evaporation Rates from Litter of Duck House
이상연 Lee Sang-yeon , 이인복 Lee In-bok , 김락우 Kim Rack-woo , 여욱현 Yeo Uk-hyeon , 데카노크리스티나 Decano Cristina , 김준규 Kim Jun-gyu , 최영배 Choi Young-bae , 박유미 Park You-me , 정효혁 Jeong Hyo-hyeog
The domestic duck industry is the sixth-largest among the livestock industries. However, 34.3% of duck houses were the duck houses arbitrarily converted from plastic greenhouses. This type of duck house was difficult to properly manage internal air temperature and humidity environment. Humidity environment inside duck houses is an important factor that directly affects the productivity and disease occurrence of the duck. Although the humidity environments of litters (bedding materials) affect directly the inside environment of duck houses, there are only few studies related to humidity environment of litters. In this study, evaporation rates from litters were evaluated according to air temperature, relative humidity, water contents of litters, and wind speed. The experimental chamber was made to measure evaporation rates from litters. Temperature and humidity controlled chamber was utilized during the conduct of the laboratory experiments. Using the measured data, a multi linear regression analysis was carried out to derive the calculation formula of evaporation rates from litters. In order to improve the accuracy of the multi linear regression model, the partial vapor pressure directly related to evaporation was also considered. Variance inflation factors of air temperature, relative humidity, partial vapor pressure, water contents of litters, and wind speed were calculated to identify multicollinearity problem. The Multiple R2 and adjusted-R2 of regression model were calculated at 0.76 and 0.71, respectively. Therefore, the regression models were developed in this study can be used to estimate evaporation rates from the litter of duck houses.
